title: Msx2 and Foxn1 regulate nail homeostasis.
abstract: Epithelial-mesenchymal interactions underlie the foundation for ectodermal appendage formation. Signal molecules such as BMPs and WNTs mediate crosstalk between the two tissue layers and coordinate both the induction and morphogenesis of ectodermal appendages. Here, we analyzed the function of two BMP downstream transcription factors, Msx2 and Foxn1, in nail differentiation. First, we show that Msx2 function is required during onychocyte (nail cell) terminal differentiation. Second, the Msx2/Foxn1/hair keratin pathway controlling hair differentiation is also conserved during onychocyte differentiation. Finally, the Msx2-/-; Foxn1-/- double-mutant nails exhibit a more severe phenotype than either single mutant including nail bed hyperplasia. Together, our data implicate important functions for Msx2 and Foxn1 in regulating differentiation of the keratogenous zone, proliferation of distal nail matrix cells, and organization of the nail bed.
authors.affiliation: Division of Dermatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Cai
authors.forename: Liang
authors.initials: L
authors.lastname: Ma
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D004475:Ectoderm / Q000502:physiology; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006724:Hoof and Claw / Q000254:growth & development*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007633:Keratins / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D008855:Microscopy, Electron, Scanning; D009024:Morphogenesis / Q000235:genetics*; D009260:Nail Diseases / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics
chemical_list: D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; C084119:MSX2 protein; C090140:Whn protein; D007633:Keratins